Tooth Contact Analysis for a Double Crowned Involute Helical Gear With Twist Free Tooth Flanks Generated by Dual Lead Hob Cutters

Abstract

To doublecrown an involute helical gear, a hobbing method is proposed by setting the hob's diagonal feed motion as a secondorder function of hob's traverse movement and modifying the tooth profile of hob cutter into a duallead form with pressure angle changed in its longitudinal direction. Merits of the proposed doublecrowning method are also verified by using three computer simulation examples to illustrate and compare the topographies of tooth flanks, contact ellipses, and transmission errors under various assembly errors of the doublecrowned gear pairs with those produced by using the conventional modified hob cutter and duallead hob cutter. Computer simulation results reveal the advantages of the proposed hobbing method for involute helical gear manufacturing.